Compatible crosslinking agents for fluorosiloxanes



United States Patent F 3,344,160 COMPATIBLE CROSSLINKIN G AGENTS FORFLUOROSILOXANES George W. Holbrook, Midland, Mich., assignor to DowCorning Corporation, Midland, Mich, a corporation of Michigan NoDrawing. Filed Oct. 7, 1963, Ser. No. 314,509 7 Claims. (Cl. 260-4482)ABSTRACTOF THE DISCLOSURE The compositions are of the class oforganosilicon compounds of the general formula which have utility asnovel, compatible crosslinking and branching agents for siloxanepolymers and copolymers. They also have utility as crosslinking agentsfor polysiloxanes that possess fluorinated hydrocarbon side chains.Illustrative of the compositions claimed herein is the compound osi(oHm1'1 S! a)2 El Illustrative of the preparation is the following:

era

3,344,160 Patented Sept.'26, 1967 Q can be hydrogen, hydroxy, or alkoxyradicals, R is a perfluoroalkyl radical of I through 8 carbon atoms, Ris selected from the-'group consisting of monovalent hydrocarbonradicals of 1 through 6 carbon atoms and CH CH R radicals, there beingno more than one of the latter attached to any one silicon atom, and ais an integer of 1 through 3.

Q can be, among others, hydrogen, hydroxyl, methoxy, ethoxy, octadecoxy,isopropoxy, hexoxy, etc.

R can be, among others, trifluor-omethyl, perfiuoroethyl,perfluorohexyl, perfluoroisopropyl, perfluorooctyl, etc.

R can be, among others, methyl, ethyl, isopropyl, hexyl, cyclohexyl,phenyl, vinyl, allyl, cyclohexenyl, 3,3,3-trifluoropropyl,fl-perfluorooctylethyl, fl-perfluoroisopropylethyl, etc.

When Q is to be hydrogen the materials of this invention can be made bythe following generic reaction in the presence of a solvent such astoluene:

The reaction usually proceeds at room temperature, or on gentle heating.It is usually exothermic, and precautions may be needed to keep thereaction temperature down.

The product will almost always be a mixture of products with varyingvalues of a. -They can be separated by fractionation. The majorfractions arethe products where a equals 1, 2 and 3.

The relative yield of the various fractions can be controlled by therelative proportions of the reactants. Thus, when a large excess of H R2s lcl is used, the primary product is that in which a is 1. When lessthan one mol of R' SiHCl per mol of RCH CH SiCI is used the primaryproducts are those where a is 2 or 3.

When Q is to be alkoxy, the materials of this invention can be made inthe following manner:

Where A is an alkyl radical. Thereaction is exothermic, so precautionmust be taken to prevent too violent a reaction through overheating.

When Q is to be hydroxy, the materials of this invention can be made inthe following manner:

The materials of this invention are useful as crosslinking and chainbranching agents for siloxane polymers and copolymers. Those materialscontaining SiH can 'be used with polymers that contain aliphaticunsaturation. The reaction can proceed in the following manner:

It should be noted that if R contains aliphatic unsaturation, the Rgroups will compete in the reaction causing the crosslinking groups tocrosslink with themselves, in part.

When Q is alkoxy or OH the materials of this invention can also be usedas crosslinking or chain branching agents for siloxane copolyrners. Thiscan be done by chydrolyzing or cocondensing the instant compositlonswith hydrolyzable silanes or other siloxanes by conventional methods.

The materials of this invention are also useful as intermediates in theproduction of fluorine-substituted homopolymers. The Q groups arehydrolyzed and condensed with each other, forming a homopolymer:

E20 homopoiymeric resin K The materials of this invention are especiallyuseful for the purpose of crosslinking polysiloxanes that containExample 1 3255 g. of dimethylchlorosilane, 4038 g. of3,3,3-trifluoropropyltrichlorosilane, and 10 liters of toluene weremixed and slowly added with stirring to 5460 g. of water. The productwas separated, Washed with water until neutral, dried, filtered andfractionated.

The following products were isolated:

consisting of 1885 g. of the product where a equals 1, 1141 g. of theproduct where a equals 2, and 346 g. of

. the product where a equals 3.

Example 2 C FaCHzCHtSiO- are obtained in which a has the value 1, 2 and3.

Example 3 When one mole of heptadecylfiuorodecyltrichlorosilane iscohydrolyzed with 1.2 moles ofheptadecylfluorodecylmethylmonochlorosilane in accordance with procedureof Example 1 the compounds I CH3 CaFnCHzCHtSiO l siCHaCHzOs n areobtained where a is 1, 2 and 3.

7 8 (r) In (1H2 (3H3 (3H2 (7H1 P CF H2CHz%iO-ilO-%1CH2CH2CF3 'l 021150356* SRCH; (OHsCHaC F3) H 2 (3111 (EB: (3B1 ('33: CFaCHaCHaSfiO SiOS|1CH2CH2CFa (I) I 002115 01115 SiCH;(CH CHqOF OCgHg 2 (1H3 CH3 CH3 I'lPt (CRF17CH2CH2)SlOSiO SlCGHzCHzCgFn) (0113x0013 l I so100 C. H I HHSlKCHaCH2Cs l1) i (IE1 CH3 (IJH: CH3

(OuFnCHsCHflSRO S|lO-Sli(CHzCHzCa u) a CH(CH3), SfiCHKCHaCHsCsFn)CH(CH3)2 o CH( That which is claimed is: 5. As a composition ofmatter 1. A composition of matter of the formula I (EB: CH: (CHa)2]lO-S'iOS!l(CH3)I H E f SKC m CH: CH2 L 6. As a composition of matterRaSlO--S10SiR: C F

Q, 1 CH: 81R:

(CH )2Sl1O-Sl-O-i(CH|)i H i H,

SK Hah .H 2

where Q is selected from the group consisting of hydro- AS a Compositionof matter gen, hydroxy, and alkoxy radicals, R is a perfluoroalkyl -(JF,-1 radical of 1 through 8 carbon atoms, R is selected from CH, the groupconsisting of monovalent hydrocarbon radicals H of 1 through 6 carbonatoms and CH CH R radicals, G there being no more than one of the latterattached to m 9 3 (C a): any one silicon atom, and a is an integer of 1through 3. H H

2. The composition of clalm 1 Where R 15 trifiuoromethyl.

3. The composition of claim 1 where R is methyl. 4. The composition ofclaim 1 where Q is H. (R f on following page) 9 10 References Cited2,967,171 1/1961 Barnes et a1. 260-448.2 UNI D A E P 3,015,585 1/1962Holbrook et a1. 260448.8 TE ST T S ATENTS 3,260,699 7/1966 Schmidt260448.8 5/1949 Patnode 260448.2 2/ 1958 Speier et a1. 260448.2 9/1960Pierce 260 448 8 5 TOBIAS E. LEVOW, Przmary Examzner. 1/ 1961 Merker260448.2 P. F. SHAVER, Assistant Examiner.

1. A COMPOSITION OF MATTER OF THE FORMULA